Research on ISAC can be generally categorized into two main directions: Dual-functional radar-communication (DFRC) and radar and communication coexistence (RCC).
The former focuses on using the same signals transmitted from one fully-shared hardware platform to simultaneously perform communication and radar sensing functionalities [1]}-[2]}.
Although it has the benefits of low power consumption and smaller-size platform, the trade-off between the radar and communication functionalities requires sophisticated optimizations on the unified dual-functional waveform.
Moreover, the resulting hardware complexity significantly hinders practical applications.
On the contrary, RCC enables separately deployed communication and radar platforms to cooperatively perform their respective functions using independent transmitted signals.
Therefore, RCC is more suitable for many existing scenarios such as sharing spectrum between air-borne early warning radars and 3.5 GHz time-division duplex long-term evolution (TDD-LTE) [3]}, [4]}, between battlefield/ground surveillance and vessel traffic service (VTS) radars and WLAN networks [5]}, [6]}, etc.
